Welding electrode coating



March 21, 1939. A. P. JOHNSTON WELDING ELECTRODE COATING Filed Oct. 19,1956 Inventor ARCHl ALD JOHNSTON Patented Mar. 21, 1939 PATENT OFFICE"WELDING ELECTRODE COATING Archibald P. Johnston, Altadena, Calii'.,assignor to Standard Oil Company of California, San Francisco, Calif., acorporation of Delaware Application October 19, 1936, Serial No. 106,423

3 (Claims.

This invention relates to a composition of material for a coated weldingelectrode and particularly to a coating for a mild steel or alloy rod tobe used in arc welding.

In'metallic arc welding the weld is produced through the agency of anelectric are established between the work and a metal rod or pencilcommonly referred to as an electrode. By associating certain materialswith the electrode as a core 10 or coating, the-operatingcharacteristics of the arc and'the quality of the deposited weld metalare greatly improved. Such materials are referred to as fluxes.

These fluxes may be of such a nature or the 15 rod to which they areapplied may be so prepared,

as by grooving or otherwise deforming its surface, that the fiuxmaterial will adhere securely thereto. It is sometimes preferable,however, to provide a fabric or otherreinforcing material 20 around asmooth rod and impregnate or fill the interstices in the fabric. Thisfabric may be applied in the form of a tape, a helical thread winding oran open mesh braid woven about the wire or rod which forms the metalbody of the electrode. e It is an object of my invention to provide afluxed electrode for producing sound ductile welds of high tensilestrength. 3 It is a further object of my invention ,to proin adown handand also an over head position, depositing a very fluid material whichis adequately protected during its deposition and coolof cotton, whichmay or may not be given a preliminary treatment with a purifying agentsuch as sodium hydroxide, or rayon or other material suitable to form areinforcing and holding structure that will enter into the flame of thearc and form products-desirable in' the shielding of the arc and theweld metal deposited thereby.

vide an electrode which will operate equally well ing by a slag which issubsequently easilyfabric covering, in this case an open mesh braid Thefabric covering 2 is filled with a flux material,3 of substantially thefollowing composition:

Percent Aluminum oxide 10 to 40 5 Manganese carbonate -l 0 to Titaniumdioxide 20 to 54 Sodium silicate (40 B.) to 35 The manganese carbonatemay be wholly or 10 partly replaced by ferro-manganese, and is to be sointerpreted in the appended claims. The titanium dioxide component maybe furnished by one or more of the natural minerals, such as rutile orilmenite. Powdered silica. up to as much 15 as 50% may be employed,particularly for rod. to be used in the down hand position. The solidmaterials are preferably in powdered form and are mixed with the sodiumsilicate to form a paste or slurry which may be diluted with water ifnecessary to produce the proper consistency for adhesion to the'rod andthe cellulosic braid. The sodium silicate acts as a binder for thecoat-' ing components as well as adding silica to the slag formed. bythe heat of the arc and the amount employed may be varied through ratherwide limits without noticeably affecting the operation of the weldingare or the characteristics of the deposited metal.

This coating may be applied'to the electrode in the following order. Thecellulosic reinforcing 2 is first wound or braided over the bare rod 1,after which the rod is passed through a bath of flux material 3, asspecified above, this paste being preferably mechanically manipulatedor, rubbed into the interstices of the braid to completely fill thesame. -In passing from this bath the coated rod is preferably'drawnthrough a die or equivalent means whereby excess paste is removed andthe thickness of the flux is limited 40 to approximately the thicknessof the braid.

Alternatively, the flux materials may be first applied to the metal rod,after whichthe fabric may be'woven, or wound or braided thereover,

either while the paste is still wet or after it has set, and additionalflux paste applied to form a smooth and dense covering.

Although thiscoating will dry within a reasonable time at atmospherictemperatures, it may be found desirable to facilitate the drying byheating the completed rod at a temperature of 200-250 F., for a periodof 1-5 minutes.

The filling material above may be "used alone as a flux, but bestresults are obtained when using it with a cellulosic material such asthe braided or woven fabric covering as described above, the weave ormesh of the fabric being so related to the threads iorming the same andto the'thickness of the flux material that the cellulosic ma terialforms from 20 to of the finished coating.

Although a specific composition and mode of making the coated weldingelectrode of this invention are described and illustrated above, it isobvious that numerous changes and variations may be made therein withoutdeparting from the scope of the following claims:

I claim: 1. A flux for use in arc welding, consisting of:

I Percent Aluminum oxide 36 Manganese carbonate M m Titanium dioxide 54;

with a'sodium silicate binder.

3. A flux for use in arc welding consisting of the following materialsin approximately the proportions given:

Percent Aluminum oxide 15 Manganese carbonate 10 Titanium dioxide a-Silica.- 15

with sodium silicate in excess of 10% to form a paste.

ARCHIBALD P. JOHNSTON"

